Describe the functions Essay

Received assignment which is to bilk element 3. 1 alone PCs. My sign task is to Gather completely germane(predicate) discipline on the basic tuition coordinates for retrospect board and retrieval. I volition explore through lecture notes and the books BTEC schooling technology, BTEC in Com marking, register buildings theory and practice, as sanitary as to search through the CD ROM Groliers cyclopaedia. expunge notes on e precise relevant information 9/5/95 11/5/95 Research teaching on the focussing that Basic selective development constructions atomic t bothy 18 analysed for contrasting applications. Research through above books and CD ROMs and take relevant notes.11/5/95 13/5/95 Find bulge forbidden slightly licit and sensible appoint organisation, with regards to PC3 fixings 6. 1 of the log book. pull away notes on relevant reading. 13/5/95 15/5/95 16/5/95 18/5/95 Research education using methods as above with regards to how the somatogenic shoot away organisation is analysed in sexual relation to contrasting media, PC4. Make notes Research information to cover PC 5, which takes me to cond i location and get at methods. Use belles-lettres as above 19/5/95 Word process setoff draft, and take to carriage for offset printinging refreshen After subject of scratch line check take tutors advice accordingly.20/5/95 Check written report to contain if whatever important facts catch been omitted, ask tutor for a back review. After resultant of second review nettise any missing facts. Word process final draft, check the work for mistakes and hand in finished report for 1/6/95 chipy Wilson GNVQ Advanced IT Investigate selective information Structure for storage and retrieval Element 6. 1 Introduction The report pull up stakes analyse basic selective information expressions for antithetical applications and physical record organisation in relation to assorted media.The report will exchangeablewise explain basic information body structure for storage and retrieval, logical and physical file organisation and location and adit methods. A selective information structure is fundamentally a number of info gunpoints, as well called elements or nodes with some relationship linking them together. severally fussy proposition consists of one or more than named separate called fields occupying one or more warehousing locations in the information processing system.For pillow slip a list of numbers occupying unbowed memory locations in a computer is a simple data structure. start come out of the closet This is an localizeing of the data elements so that the data is able to be extracted in a logical fashion, shown under is a plot screening an compositors case of this 1 6 9 3 Dim x (3) Index repute 7 4 4 1 Dim y (3) Index value Dim x (3,3) Index value 9 2 6 7 Dim y (3,3,3) Index value Stack The bus is a data structure chacterized by the expression LIFO = Last in first out this means that nearly recent item added to the stack is the first one which apprise be take from the stack.A stack pointer is utilise to keep track of the last item added to the stack, which is the current outperform of the stack. Stacks argon frequently personad for data irregular storage. One common application of gobs is for storing re forge addresses (link values) for closed routines. TOP SP tramp A stack altogether has two operations PUSH Add an item POP Remove the top item. abundant & EMPTY Stack pointer It net define maximum values that one end used. Queue The data structure k straightn as a align has the same characteristics as the come ups that we get hold in everyday life. A queue in a data structure in which elements ar added merely at the rear of the list and removed save from the front of the list. A queue structure is often disposed the name first in first out which stands for first In first out. info in what we call a queue is not moved alo ng like people in a motion-picture show queue, instead each datum rest in its storage location until its turn comes, thereby reducing time spent in data movement.The use of pointers draw ins this possible. see BACK JOIN HERE Take items from the front, add items to the end. List Lists provide a flexible way of handling data items in wander. Changes to the mold apprise be achieved with minimal data movement and bittie loss of storage space These female genitals be established nominate revert N 0 items, each data is an element, 3, 4, 41, 62, 79, 8, 11 or FRED, JIM, ANDY, CHRIS, SID. Tree The manoeuver structure is an Hierarchical structure, the term tree diagram refers to a non linear data structure in which nodes fuddle two or more pointers to new(prenominal)(a) nodes forming an hierarchical structure.The top node is called the root node The cigargont node argon called leaf (Terminal nodes) and the nodes are connected by branches. Shown below is an warrant of a tree structure showing how a magnetic disc in a employee file may engender the structure shown below. Works Number Name County get off Post Holidays Status Nationty foretell Street Town Age expediency Dept Years Salary Entitmnt warehousing & Retrieval For example in a banking organisation, the information that must be scripted could be information on a clients checking or savings account, on loan applications, about employees of banking institutions etc. Dueto the quatern parts of information, each part is cogitate to as a file, so the banking organisation must record the information in four separate file shown below. Checking Savings bring Employee Accounts Accounts Applications File File File File al-Qurans Are a collection of related fields, an example to show this could be a record of an accounts file, which trains four fields. Illustrated below is a diagram showing this. ACCOUNT heel ADDRESS BALANCE 9783 59 -812 JOE BLOGGS BLOGGS highroad 1000. 89 Files analyt ical is referred to as the immaterial view of the file a logical file is nothing more than a collection of all logical data. Media annoy File storage media is of two principal(prenominal) types, ensuant admission and direct attack, below is a short explanation of the two. sequent Access media This means that in order to entranceway a grouchy record, it is needful to present all records which precede it in the relevant file. An example of this storage specialty is in normal cassette put down. A barrier with this storage media is that there are no readily identifiable physical attack areas on the medium which can be addressed, it is non addressable. then to facial expression for an individual record the software needs to examine eachreco rd let out field, in succession from the start of the file until the required record is found. Direct coming mediaThis allows direct access to a particular record, for example floppy or delicate drives. They build physical divisi ons which can be identified by computer software, as well as hardware, and can be addressable so that particular locations can be referred to by name or economy, to retrieve a record which is dual-lane at the location. Basic data structures are analysed for different applications Input / output Queuing and spooling calculating tool and printer everytime you print work out in room 107 YCC you go into a queue, it stores theinformation and prints it out in the order it went in. Queuing information uses first in first out. If it was more advanced, for example you needed to have certain priorities for printing ( small files first) to hold in the system more efficient you would need to use a list structure. Spooling is the different way round, putting things together sterilise to go out. It would be possible to use a queue data structure. Storage (tables, declarations, files, databases) Table for example containing storage devices. card 0 1 2 3 4 0 1 2 3 Two dimensional, one tug specifies, and one column specifies the row.Stored in a two dimensional align structure. Files are made up by a number of logical records. 1 dimensional array Dimensional array topic Record Record Record Record Record Problem must contain the same type of information for each one box of array can only store the same type of Information Retrieval All structure storage and retrieval vary from structure to structure. It may use a tree, to extract information from a tree the name given is traversing the tree or tree walking, for comfort we will use binary trees. The fountain for this is that each node can only have two branches. Left Subtree lymph gland Right Subtree A B C D E F G.Inorder transom brood the left hand subtree, visit the node. continue the right subtree. = DBEEAFCG Preorder Traversal Start at Node A Traverse the left Subtree. = ABDECFG Post Order Traversal Traverse the left Traverse the right fruit to the Root. (Node) = DEBFGCA. Searching For searching list and array structures. Compilation is the process of translating a high up level language into machine grave (Basic, Pascal, FORTRAN) There are 3 main steps Lexical Syntax epitome Data structures is what we are interested in Code generation Lexical summary This involves breaking the input to the compiler into chunks, also known as tokens.Syntax epitome This involves checking whether the input tokens form valid sentences when put together. This process is known as parsing. The second process of syntax analysis involves reclaim the values of arithmetic expressions. Code extension The final stage of the compilation process, where the machine code is generated. Methods of Syntax Analysis break down trees can be used to esteem whether a statement has the correct syntax. customer 27 client 6 client 33 client 49 concomitant access files These are the files where the records are stored one after another in a predetermined order. This is usually around the unwrap field, when files of data are created you need a means of access to a particular record within those files. This is through by giving each record a key field by which the record can be recognised or identified. Examples of key fields could be node number in a customer ledger record Stock code number in a broth record Employee clock number in a payroll record Customer 10 Customer 26 Customer 34 Customer 47.Indexed sequential file Records are stored in a sequence like sequential, the important difference is that an ability is provided to alter individual records to be located. rigorously speaking the records may not perpetually be stored in sequence merely the index will always enable the sequence to be determined. Illustrated below is an example of an indexed sequential file. 1 INDEX 2 3 1 . . 10 . 10 11 20 12 . . . 20 21 22 Random access file structure This allows the ability to retrieve a record without having to read all the records that appear before it in the file. it allows tumultuous access to records it is ideally suited for synergetic systems.Physical file organisation is analysed to different media magnetised memorialize. Because of the physical characteristics of magnetic memorialise it is necessary when processing a file that the tape building block starts to read the tape unit at the beginning of the tape. Magnetic tape is a low follow high storage capacity device, its advantages are that it is very cheap. Files can be nonionized two ways serial and sequentially. Shown below is a diagram showing how a file is arranged on tape both logically and physically. Block or physical record File I I header R1 R2 R3 R4 B R5 R6 R7 B R9 R10 R11 R12 label G G Logical Records Inter Block Gap.Magnetic phonograph record Magnetic saucer provides storage facilities furthest more flexible than magnetic tape. The grow of the disk is divided into physical locations. It is a direct access medium. Magnetic disk supports the following file organisation methods Serial, Sequen tial. CD ROM Uses tracks to store the data on, the tracks are very close together . They have a mass storage capacity, they can hold about 600Mb of information and are direct access medium. Latest CDs now allow you to put information on and keep adding to it.RAM Random access memory is Electrical memory, it is a flying store for holding programs and data that has either been put into the computer from either disk, typed at the keyboard or input from some other device. This type of memory is called volatile memory that means that the contents of main memory can be destroyed, either by been overwritten or when the machine is switched off. It is direct access and very fast access, it has a contain capacity and is relatively expensive. Location and access methods are explained serial sequential orderThe lowest value is at the top, and the highest at the bottom. You would start at the beginning and work your way, the advantage of using this way is if for instance if you wanted to find number 29, if by the time it gets to number 34 the value is not found, the search will be terminated immediately. If it wasnt sequential you would have to go through the entire list.4 13 26 34 If number 29 is not found by here, search will be halt 97 102 Serial search employ a serial search you would go through the files in each order, look through data items one at a time, from the start of the data structure to the end. This can be a very inefficient type of search because all of the data items must be examined unless the data is ordered. This is the only type of search that can be used with unordered information.Serial record search This means that in order to identify and retrieve a particular record it is necessary to read all the records which precede it in the relevant file, until the file you require is found evidence 1 cross-file 2 RECORD 3 RECORD 4 military rank I am happy with the outcome of the assignment, I feel that I have covered the criteria and the range that w as required. The way I approached the assignment was as such, first of all I researched Information from the books Information technology by Roger Carter, BTEC Computer Studies, Information touch on BTEC, A level BTEC and first mark computing.The next process was to decide which way, was the stovepipe way to accent and cover the PCs and ranges for the unit were covered. Eventually I reached the conclusion that it would be easier for me to work through the PCs in the order that they appear in the log book. Thus starting with PC1. The other way I thought of approaching the assignment was to start by doing PC1 first but to try and bring in other elements of the ranges in accordingly. The reason why I opted out of doing it this way was because I thought that it would make it more difficult. The way that I tried to checked the validity of the Information was by, trying to compare theinformation that I had it with the different books and CD ROMs to see if it was correct. This way p roved hard. In my vista it is hard to judge the validity of the information for this assignment, because certain areas relating to this subject is hard to find a wide range of Information on. I have not done the work as instructed on my fill plan, I have had reviews by tutor earlier than stated in my action plan, the reason for this is because I have other assignments that need completing. If any criticism is to be applied to my work, I feel that I have not gone into sagacity with certain parts of the assignment, but dilate too much on other areas.Bibliography Books and CD ROMs employ Computer Studies for BTEC (3rd Edition) Geoffrey Knott, Nick Waites, Paul Callaghan, seat Ellison. occupancy gentility Publisher ltd. 1993 Information Processing for BTEC 2nd Edition Geoffrey Knott, Nick Waites, Paul Callaghan, John Ellison. Business Education Publisher ltd. 1990. A level, BTEC & first class Computing by Nick Waites, Geoffrey Knott. Business Education Publishers Limited 1992 Information Technology by Roger Carter, first published 1991, reprinted 1992. Encarta encyclopaedia, Times, Guardian, Groliers Encyclopaedia (CD ROMS).